Field removable bonnet assemblies for use with valves

ABSTRACT

Field removable bonnet assemblies for use with valves are described herein. An example field removable bonnet assembly for use with internal valves includes a body that is to be removably coupled to the internal valve. The body defines a bore that is to receive a valve packing. Additionally, the field removable bonnet assembly includes a shaft having a cam assembly that is to rotatably engage a stem of the internal valve. The shaft is rotatably coupled to the body and the shaft is at least partially positioned within the bore. Further, the field removable bonnet assembly includes a removable adjuster that is externally accessible to enable an adjustment of the removable adjuster relative to the body to change a force exerted by the valve packing on the shaft. The removable adjuster is field removable to replace or repair the valve packing.

FIELD OF THE DISCLOSURE

This patent relates generally to field removable bonnet assemblies and,more specifically, to field removable bonnet assemblies for use withvalves.

BACKGROUND

Internal valves are used in a variety of commercial and industrialapplications to control fluid flow between a fluid storage container andanother container, hose, pipeline, etc. Typically, internal valves areprovided with a bonnet assembly that includes a shaft coupled to a camthat rotatably engages a stem to open and close the internal valve.

Bonnet assemblies of known internal valves include a spring that exertsa force on a valve packing to urge the valve packing against a portionof the shaft. The engagement between the valve packing and the shaftcreates a substantially bubble tight seal to prevent fluid from exitingthrough the bonnet assembly. In time, the resilience of the valvepacking and the amount of force that the spring exerts on the valvepacking decrease, which may enable fluid to exit through the bonnetassembly between the shaft and the valve packing.

In some instances, the fluid storage container in which the internalvalve is mounted is located in a rural location in which repairtechnicians and/or replacement parts are not readily available. As aresult, if a bubble tight seal does not exist between the shaft and thevalve packing, the internal valve may be inoperable and/or aconsiderable amount of fluid may exit through the bonnet assembly beforethe internal valve is repaired and/or replaced.

SUMMARY

In accordance with a disclosed example, an internal valve includes afirst body having external threads to threadably engage another bodyhaving a pressurized chamber. The first body defines a second chamberand a seating surface. Additionally, the internal valve includes a stemassembly having at least one biasing element. The stem assembly is toexert a force on a fluid flow control member to urge the fluid flowcontrol member toward the seating surface. Further, the internal valveincludes a field removable bonnet assembly that is removably coupled tothe first body and at least partially positioned within the secondchamber. The field removable bonnet assembly includes a second body thatdefines a bore and a shaft having a cam assembly that is to rotatablyengage a portion of the stem assembly to move at least a portion of thefluid flow control member relative to the first body to control a flowof fluid between the pressurized chamber and the second chamber. Theshaft is rotatably coupled to the second body and the shaft is partiallypositioned within the bore. Additionally, the field removable bonnetassembly includes a removable adjuster that is externally accessible toenable an adjustment of the removable adjuster relative to the secondbody to change a force exerted by a valve packing on the shaft. Theremovable adjuster is field removable to replace or repair the valvepacking.

In accordance with another disclosed example, a field removable bonnetassembly for use with internal valves includes a body that is to beremovably coupled to the internal valve. The body defines a bore that isto receive a valve packing. Additionally, the field removable bonnetassembly includes a shaft having a cam assembly that is to rotatablyengage a stem of the internal valve. The shaft is rotatably coupled tothe body and the shaft is at least partially positioned within the bore.Further, the field removable bonnet assembly includes a removableadjuster that is externally accessible to enable an adjustment of theremovable adjuster relative to the body to change a force exerted by thevalve packing on the shaft. The removable adjuster is field removable toreplace or repair the valve packing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a known internal valve.

FIG. 2A depicts a portion of an example internal valve including anexample field removable bonnet assembly.

FIG. 2B depicts a top view of an example removable adjuster that may beused to implement the example field removable bonnet assembly of FIG. 2Ain which a plurality of slots of the removable adjuster aresubstantially perpendicular to a longitudinal axis of the internal valveof FIG. 2A.

FIG. 2C depicts a top view of an example removable adjuster that may beused to implement the example field removable bonnet assembly of FIG. 2Ain which the plurality of slots of the removable adjuster aresubstantially parallel to the longitudinal axis of the internal valve ofFIG. 2A.

FIG. 3 depicts the example field removable bonnet assembly of FIG. 2A.

FIG. 4 depicts an alternative example removable adjuster that may beused to implement the field removable bonnet assembly of FIGS. 2A and 3.

FIG. 5 depicts an alternative example field removable bonnet assemblythat may be used to implement the internal valve of FIG. 2A.

DETAILED DESCRIPTION

Certain examples are shown in the above-identified figures and describedin detail below. In describing these examples, like or identicalreference numbers are used to identify the same or similar elements. Thefigures are not necessarily to scale and certain features and certainviews of the figures may be shown exaggerated in scale or in schematicfor clarity and/or conciseness. Additionally, several examples have beendescribed throughout this specification. Any features from any examplemay be included with, a replacement for, or otherwise combined withother features from other examples.

The example field removable bonnet assemblies described hereinadvantageously enables a technician to externally adjust a force exertedby a valve packing on a shaft of an internal valve to substantiallyprevent fluid from exiting the internal valve to the atmosphere, whicheliminates the problems associated with bonnet assemblies of knowninternal valves. In particular, the examples described herein areprovided with a removable adjuster that can be externally adjusted tochange a force exerted by a valve packing on a shaft. Additionally, theremovable adjuster may be advantageously removed in the field while theinternal valve is coupled to a service line or chamber to replace and/orrepair the valve packing, a spring and/or packing rings within theexample field removable bonnet assembly. Further, the example fieldremovable bonnet assemblies may be advantageously removed from theinternal valve in the field while the internal valve is coupled to aservice line or chamber to replace and/or repair the field removablebonnet assembly.

In some examples described herein, the removable adjuster defines aplurality of slots that enables a technician to externally adjust theremovable adjuster relative to the internal valve. The position of theseslots relative to the internal valve may indicate the position of theremovable adjuster and, specifically, indicate the amount that theremovable adjuster may be adjusted to further compress the valvepacking. In other examples described herein, the removable adjusterincludes an elongated member that extends from a body of a bonnet toenable a technician to externally adjust the removable adjuster relativeto the internal valve. This elongated member may have a laser marking orother markings to indicate the position of the removable adjuster and,specifically, indicate the amount that the removable adjuster may beadjusted to further compress the valve packing.

FIG. 1 depicts a known internal valve 100 that has a body 102, a poppet104, and a bonnet assembly 106. The bonnet assembly 106 is coupled tothe body 102 and the poppet 104 sealingly engages a surface 108 of thebody 102 to control fluid flow through the internal valve 100.

The body 102 includes exterior threads 110 that engage an opening (notshown) of a chamber or tank (not shown) such as a pumping system, astationary storage tank, transport truck, etc. Additionally, the body102 defines a bore 112 having a first opening 114 and a second opening116 to fluidly couple the chamber or tank to another chamber, a hose, apipeline, etc. Specifically, the bore 112 includes internal threads 118to threadingly engage another body (not shown) such as, for example, acoupling of an LPG hose.

The bonnet assembly 106 is coupled to the body 102 via a plate 120. Thebonnet assembly 106 includes a shaft 122 that is partially positionedwithin and rotationally coupled to a bonnet 124. Specifically, a portionof the shaft 122 is positioned within a bore 126 defined by the bonnet124 along with a spring 128 that exerts a force against a valve packing130 to urge the valve packing 130 against the shaft 122 to substantiallyprevent fluid from exiting through the bonnet assembly 106 between theshaft 122 and the valve packing 130. Additionally, packing rings 131 arepositioned on either side of the valve packing 130 and engage the plate120 and the spring 128. The plate 120 positions the spring 128, thevalve packing 130 and the packing rings 131 within the bore 126.Typically, the engagement between the shaft 122 and the valve packing130 of newly manufactured bonnet assemblies 106 creates a bubble tightseal that prevents fluid from exiting through the bonnet assembly 106.However, exposure to substances and/or chemicals corrode the spring 128and/or the valve packing 130, which degrades this bubble tight seal and,as a result, may enable fluid to exit through the bonnet assembly 106.

The shaft 122 includes an external lever 132 to rotate the shaft 122relative to the bonnet 124 and the body 102. A cam 134 is coupled to theshaft 122 opposite the external lever 132 and is positioned within thebore 112. As the shaft 122 is rotated, the cam 134 engages a surface 136to move a stem assembly 138 within the bore 112.

The stem assembly 138 includes a stem 140, a first spring 142, a secondspring 144 and a plug 146. A first spring seat 148 is coupled to an end150 of the stem 140 and is positioned opposite a second spring seat 152that surrounds the stem 140. A surface 154 of the second spring seat 152engages a guide bracket 156 that guides the stem 140 relative to thebody 102. The first spring 142 is positioned between the first springseat 148 and the second spring seat 152 and the second spring 144 ispositioned between the second spring seat 152 and the poppet 104. Theplug 146 is coupled to the stem 140 opposite the first spring seat 148and engages a seating surface 158 defined by the poppet 104.Additionally, a portion of the stem 140 is positioned within an aperture160 defined by the poppet 104 adjacent the seating surface 158.

In practice, to equalize a pressure between a chamber or tank in whichthe internal valve 100 is mounted and the other chamber, hose, pipeline,etc. coupled to the second opening 116, the external lever 132 isrotated to position the cam 134 at a mid-point (e.g., 70° travel), whichmoves the stem assembly 138 to disengage the plug 146 from the seatingsurface 158 and positions a cut-away portion or groove 162 of the stem140 adjacent to the aperture 160. Positioning the cut-away portion orgroove 162 adjacent to the aperture 160 increases the size of a fluidflow channel 164 between the stem 140 and a surface 166 of the aperture160, which enables a relatively large amount of fluid to bleed betweenthe chamber or tank and the other chamber, hose, pipeline, etc. toequalize the pressure across the internal valve 100.

Once the fluid pressure is equalized, the internal valve 100 may befully opened. Specifically, the external lever 132 may be rotated toposition the cam 134 at a high-point, which moves the stem assembly 138to enable a seating surface 168 of the poppet 104 to disengage thesurface 108 to allow fluid to flow from the chamber, tank, etc. in whichthe internal valve 100 is mounted through the first opening 114 to thesecond opening 116. However, if the fluid flow increases to a magnitudegreater than a predetermined fluid flow (e.g., an excess flow limit), aforce exerted by the fluid flow against an external surface 170 of thepoppet 104 overcomes a force exerted by the second spring 144 and causesthe seating surface 168 of the poppet 104 to reengage the surface 108even though the cam 134 is positioned at the high-point. In thisposition, while the seating surface 168 of the poppet 104 engages thesurface 108, the plug 146 is at a distance from the seating surface 158and a cylindrical portion 172 of the stem 140 is positioned adjacent theaperture 160. Positioning the cylindrical portion 172 adjacent theaperture 160 decreases the size of the fluid flow channel 164 betweenthe stem 140 and the surface 166 of the aperture 160, which enables arelatively small amount of fluid to bleed between the chamber or tank inwhich the internal valve 100 is mounted and the second opening 116.

FIG. 2A depicts a portion of an internal valve 200 that includes a body202 and an example field removable bonnet assembly 204. The fieldremovable bonnet assembly 204 includes a bonnet 206 having a body 208and a shaft 210 coupled to a cam 212. Additionally, the field removablebonnet assembly 204 includes a spring 214, a first packing ring 216, asecond packing ring 218, a valve packing 220 and an example removableadjuster 222. For clarity, certain portions of the internal valve 200are excluded such as, for example, the stem assembly 138 and the poppet104 of FIG. 1.

As discussed above, the body 202 includes exterior threads 224 thatengage an opening (not shown) of a chamber or tank (not shown) such as apumping system, a stationary storage tank, transport truck, etc.Additionally, the body 202 defines a first bore 226 having a firstopening (not shown) (e.g., substantially similar to the first opening114 of FIG. 1) and a second opening 228 to fluidly couple the chamber ortank to another chamber, a hose, a pipeline, etc. Specifically, thefirst bore 226 includes internal threads 230 to threadingly engageanother body (not shown) such as, for example, a coupling of an LPGhose.

The body 202 defines a second bore 232 into which the field removablebonnet assembly 204 is positioned. A diameter of the second bore 232substantially corresponds to a diameter of the body 208. Additionally,the second bore 232 defines a stepped portion 234, which is engaged by astepped portion 235 of the body 208 via a seal 237 to properly positionthe field removable bonnet assembly 204 within the second bore 232. Theseal 237 (e.g., an o-ring or gasket) is positioned between the steppedportions 234 and 235 to create a seal between the body 202 of theinternal valve 200 and the body 208 of the bonnet 206 to substantiallyprevent fluid from exiting to the atmosphere through the second bore232.

The body 208 of the bonnet 206 defines a first bore 236 and a secondbore 238 that is smaller than the first bore 236. Generally, a diameterof the first bore 236 substantially corresponds to a diameter of thespring 214 that is positioned within the first bore 236, and a diameterof the second bore 238 corresponds to a diameter of the shaft 210.Additionally, the body 208 defines internal threads 240 that correspondto threads 242 of the removable adjuster 222. A stepped portion 241 isdefined between the internal threads 240 and the first bore 236 to limitthe movement of the removable adjuster 222. Specifically, the steppedportion 241 prevents the removable adjuster 222 from over compressingthe spring 214 and/or the valve packing 220.

The spring 214 surrounds the shaft 210 and is positioned within thefirst bore 236 between a surface 244 of the first bore 236 and the firstpacking ring 216. The valve packing 220 surrounds the shaft 210 and ispositioned within the first bore 236 between the first packing ring 216and the second packing ring 218, which each at least partially surroundthe shaft 210. The second packing ring 218 is positioned between thevalve packing 220 and the removable adjuster 222.

To couple the field removable bonnet assembly 204 to the body 202, theinternal valve 200 is provided with a plate 245 that is coupled to thebody 202 via a plurality of fasteners 246.

In practice, the spring 214 exerts a force against the valve packing 220via the first packing ring 216 to compress the valve packing 220 and tourge the valve packing 220 against the shaft 210 to create a bubbletight seal that substantially prevents fluid from exiting to theatmosphere between the shaft 210 and the valve packing 220. Theremovable adjuster 222 is coaxially aligned with the first bore 236 anddefines an aperture 247 that surrounds the shaft 210. Additionally, theremovable adjuster 222 threadingly engages the internal threads 240 toposition the spring 214, the first and second packing rings 216 and 218and the valve packing 220 within the first bore 236.

Turning back to FIG. 1, as the spring 128 is exposed to substancesand/or chemicals, a spring force of the spring 128 decreases, whichreduces the force exerted against the packing ring 131 to urge the valvepacking 130 against the shaft 122. Additionally, as the valve packing130 is exposed to substances and/or chemicals, the bubble tight sealbetween the valve packing 130 and the shaft 122 diminishes, which mayenable fluid to exit through the bonnet assembly 106. In practice, thefluid storage container in which the internal valve 100 is mounted maybe located in a rural location in which repair technicians and/orreplacement parts are not readily available. Unfortunately, if a bubbletight seal does not exist between the shaft 122 and the valve packing130, the internal valve 100 may be inoperable and/or a considerableamount of fluid may exit through the bonnet assembly 106 before theinternal valve 100 is repaired and/or replaced.

In contrast, the example field removable bonnet assembly 204 of FIG. 2Ais provided with the removable adjuster 222 that is externallyaccessible to adjust the removable adjuster 222 relative to the body208. Specifically, in some examples, the removable adjuster 222 definesa plurality of slots 248 that corresponds to a tool (not shown) toenable adjustment of the removable adjuster 222. In practice, if abubble tight seal does not exist between the shaft 210 and the valvepacking 220 and/or fluid is exiting to the atmosphere through the body208 of the bonnet 206, the removable adjuster 222 may be manually turned(e.g., rotated) to increase the force against the valve packing 220.Specifically, manually turning the removable adjuster 222 compresses thevalve packing 220 and causes the valve packing 220 to more tightlyengage the shaft 210 to recreate a substantially bubble tight sealbetween the shaft 210 and the valve packing 220 to at least partiallyeliminate the flow of the fluid to the atmosphere. As the removableadjuster 222 is manually turned, a cylindrical member 250 of theremovable adjuster 222 may move at least partially within the first bore236 as it compresses the valve packing 220.

In some examples, the position of the slots 248 indicates the positionof the removable adjuster 222 relative to the body 208. In practice, forexample, if the slots 248 are approximately perpendicular to alongitudinal axis 251 of the body 202 of the internal valve 200, asshown in FIGS. 2A and 2B, the removable adjuster 222 may be able tocompress the valve packing 220 an additional one-sixteenth of an inchbefore the removable adjuster 222 engages the stepped portion 241.Alternatively, for example, if the slots 248 are approximately parallelto the longitudinal axis 251 of the body 202 of the internal valve 200,as shown in FIG. 2C, the removable adjuster 222 may be able to compressthe valve packing 220 an additional one-thirty second of an inch beforethe removable adjuster 222 engages the stepped portion 241.

The shaft 210 includes an external lever 252 to rotate the shaft 210relative to the body 208 of the bonnet 206. The cam 212 is coupled tothe shaft 210 via a fastener 254 opposite the external lever 252 and ispositioned within the first bore 226. As the shaft 210 is rotated, thecam 212 engages the surface 136 (FIG. 1) to move the stem assembly 138(FIG. 1) within the bore 112 (FIG. 1).

In practice, to equalize a pressure between a chamber or tank in whichthe internal valve 200 is mounted and the other chamber, hose, pipeline,etc. coupled to the second opening 228, the external lever 252 isrotated to position the cam 212 at a mid-point (e.g., 70° travel), whichmoves the stem assembly 138 (FIG. 1) to disengage the plug 146 (FIG. 1)from the seating surface 158 (FIG. 1) and positions the cut-away portionor groove 162 (FIG. 1) of the stem 140 (FIG. 1) adjacent to the aperture160 (FIG. 1). As discussed above, positioning the cut-away portion orgroove 162 (FIG. 1) adjacent to the aperture 160 (FIG. 1) increases thesize of the fluid flow channel 164 (FIG. 1) between the stem 140(FIG. 1) and the surface 166 (FIG. 1) of the aperture 160 (FIG. 1),which enables a relatively large amount of fluid to bleed between thechamber or tank and the other chamber, hose, pipeline, etc. to equalizethe pressure across the internal valve 200.

Once the fluid pressure is equalized, the internal valve 200 may befully opened. Specifically, the external lever 252 may be rotated toposition the cam 212 at a high-point, which moves the stem assembly 138(FIG. 1) to enable the seating surface 168 (FIG. 1) of the poppet 104(FIG. 1) to disengage the surface 108 (FIG. 1) to allow fluid to flowfrom the other chamber, tank, etc. in which the internal valve 200 ismounted through the first opening 114 (FIG. 1). However, if the fluidflow increases to a magnitude greater than a predetermined fluid flow(e.g., an excess flow limit), a force exerted by the fluid flow againstthe external surface 170 (FIG. 1) of the poppet 104 (FIG. 1) overcomes aforce exerted by the second spring 144 (FIG. 1) and causes the seatingsurface 168 (FIG. 1) of the poppet 104 (FIG. 1) to reengage the surface108 (FIG. 1) even though the cam 212 is positioned at the high-point. Inthis position, while the seating surface 168 (FIG. 1) of the poppet 104(FIG. 1) engages the surface 108 (FIG. 1), the plug 146 (FIG. 1) is at adistance from the seating surface 158 (FIG. 1) and the cylindricalportion 172 (FIG. 1) of the stem 140 (FIG. 1) is positioned adjacent theaperture 160 (FIG. 1). As discussed above, positioning the cylindricalportion 172 (FIG. 1) adjacent the aperture 160 (FIG. 1) decreases thesize of the fluid flow channel 164 (FIG. 1) between the stem 140(FIG. 1) and the surface 166 (FIG. 1) of the aperture 160 (FIG. 1),which enables a relatively small amount of fluid to bleed between thechamber or tank and the second opening 228.

To install (e.g., retrofit) and/or replace the example field removablebonnet assembly 204 on the internal valve 200, the fluid pressure isreduced (e.g., drained) from the chamber or tank and the plurality offasteners 246 are then removed from the plate 245. The plate 245 is thenremoved from the body 202 and the field removable bonnet assembly 204 isthen removed from the second bore 232. Next, the seal 237 is removed andreplaced and then a replacement field removable bonnet assembly 204 isinserted into the second bore 232 until the stepped portion 235 of thebody 208 is adjacent the seal 237. The plate 245 may then be reattachedto the body 202, and the removable adjuster 222 may be adjusted toensure a substantially bubble tight seal between the shaft 210 and thevalve packing 220.

Alternatively, to replace the spring 214, the packing rings 216 and 218and/or the valve packing 220 of the field removable bonnet assembly 204while the field removable bonnet assembly 204 is coupled to the body 202of the internal valve 200, the fluid pressure is reduced (e.g., drained)from the chamber or tank and the removable adjuster 222 is then removedfrom the body 208 of the bonnet 206. Next, the second packing ring 218,the valve packing 220, the first packing ring 216 and the spring 214 areremoved and then replaced. The removable adjuster 222 may then bereattached to the body 208 and adjusted to compress the spring 214 toexert a force against the valve packing 220 to create a substantiallybubble tight seal between the shaft 210 and the valve packing 220.

FIG. 3 depicts the field removable bonnet assembly 204 of FIG. 2A, whichis separated from the internal valve 200 (FIG. 2A). Specifically, FIG. 3depicts the field removable bonnet assembly 204 prior to being installedon the internal valve 200 (FIG. 2A). Reference numbers used in FIG. 3are the same as reference numbers used in FIG. 2A in describing thefield removable bonnet assembly 204. As such, the description relatingto these reference numbers will not be repeated here.

FIG. 4 depicts an alternative example removable adjuster 400 that can beused to implement the field removable bonnet assembly 204 of FIGS. 2Aand 3. The removable adjuster includes a body 402 having a cylindricalmember 404, a central portion 406 and an elongated member 408. The body402 defines an aperture 410 to receive the stem 210 (FIG. 2A).

The cylindrical member 404 may be moved within the first bore 236 (FIG.2A) of the bonnet 206 (FIG. 2A) as the removable adjuster 400 isadjusted. Additionally, the cylindrical member 404 has a surface 412that engages the second packing ring 218 (FIG. 2A). The central portion406 is provided with external threads 414 that are to threadingly engagethe internal threads 240 (FIG. 2A) of the bonnet 206 (FIG. 2A).

If the removable adjuster 400 threadingly engages the internal threads240 (FIG. 2A), the elongated member 408 extends from the bonnet 206. Theelongated member 408 has a surface 416 that may be engaged by a tooland/or wrench (not shown) to turn (e.g., rotate) the removable adjuster400 relative to the bonnet 206 (FIG. 2A). In some examples, theelongated member 408 may have a hexagonal profile. However, theelongated member 408 may have any other suitable profile. Additionally,the surface 416 may include a laser marking 418 or any other suitableindicator to indicate the position of the removable adjuster 400relative to the body 208 (FIG. 2A). In practice, for example, if thelaser marking 418 is substantially parallel to a longitudinal axis 420of the body 402 and the laser marking 418 is positioned toward the firstopening 114 (FIG. 1), the removable adjuster 400 may be adjusted tocompress the valve packing 220 (FIG. 2A) an additional one-sixteenth ofan inch before a surface 422 of the removable adjuster 400 engages thestepped portion 241 (FIG. 2A). Alternatively, for example, if the lasermarking 418 is substantially parallel to the longitudinal axis 420 ofthe body 402 and the laser marking 418 is positioned toward the secondopening 228 (FIG. 2A), the removable adjuster 400 may be adjusted tocompress the valve packing 220 an additional one-thirty second of aninch before the surface 422 of the removable adjuster 400 engages thestepped portion 241 (FIG. 2A).

FIG. 5 depicts an alternative field removable bonnet assembly 500 thatmay be used to implement the internal valve 200 of FIG. 2A. The fieldremovable bonnet assembly 500 is substantially similar to the fieldremovable bonnet assembly 204 (FIG. 2A). Reference numbers used in FIG.5 that are the same as the reference numbers used in FIG. 2A correspondto portions on the field removable bonnet assembly 500 that are the sameor substantially similar to the portions on the field removable bonnetassembly 204 (FIG. 2A). As such, the description relating to thesereference numbers will not be repeated here.

As described above, the field removable bonnet assembly 500 includes abonnet 502 having a body 504 and the shaft 210 coupled to the cam 212.Additionally, the field removable bonnet assembly 500 includes thespring 214, the first packing ring 216, the second packing ring 218, thevalve packing 220 and the removable adjuster 222.

In contrast to the field removable bonnet assembly 204 of FIG. 2A, thebody 504 includes exterior threads 506 that correspond to internalthreads (not shown) on the second bore 232 (FIG. 2A) to couple the fieldremovable bonnet assembly 500 to the internal valve 200 (FIG. 2A). Inpractice, to couple the field removable bonnet assembly 500 to theinternal valve 200, the exterior threads 506 are threaded into theinternal threads of the second bore 232 (FIG. 2A). In this example, aportion 508 of the bonnet 502 may extend from the body 202 to enable atool (not shown) to engage the portion 508 to rotate the field removablebonnet assembly 500 relative to the internal valve 200 (FIG. 2A) toensure that the field removable bonnet assembly 500 is properlypositioned within the second bore 232 (FIG. 2A).

Although certain example methods, apparatus and articles of manufacturehave been described herein, the scope of coverage of this patent is notlimited thereto. On the contrary, this patent covers all methods,apparatus and articles of manufacture fairly falling within the scope ofthe appended claims either literally or under the doctrine ofequivalents.

1. An internal valve, comprising: a first body having external threadsto threadably engage another body having a pressurized chamber, whereinthe first body defines a second chamber and a seating surface; a stemassembly having at least one biasing element, wherein the stem assemblyis to exert a force on a fluid flow control member to urge the fluidflow control member toward the seating surface; and a field removablebonnet assembly that is removably coupled to the first body and at leastpartially positioned within the second chamber, wherein the fieldremovable bonnet assembly comprises: a second body that defines a bore;a shaft having a cam assembly that is to rotatably engage a portion ofthe stem assembly to move at least a portion of the fluid flow controlmember relative to the first body to control a flow of fluid between thepressurized chamber and the second chamber, wherein the shaft isrotatably coupled to the second body and wherein the shaft is partiallypositioned within the bore; and a removable adjuster that is externallyaccessible to enable an adjustment of the removable adjuster relative tothe second body to change a force exerted by a valve packing on theshaft, wherein the removable adjuster is field removable to replace orrepair the valve packing.
 2. The internal valve as defined in claim 1,wherein the removable adjuster further comprises an indicator toindicate an adjustment position of the removable adjuster relative tothe second body.
 3. The internal valve as defined in claim 1, whereinthe removable adjuster further defines at least one slot to be engagedby a tool to enable the adjustment of the removable adjuster relative tothe second body.
 4. The internal valve as defined in claim 3, wherein aposition of the at least one slot is to indicate an adjustment positionof the removable adjuster relative to the second body.
 5. The internalvalve as defined in claim 1, wherein the removable adjuster comprises anelongated member that extends from the second body to enable theadjustment of the removable adjuster relative to the second body.
 6. Theinternal valve as defined in claim 1, wherein the removable adjusterthreadingly engages the second body.
 7. The internal valve as defined inclaim 1, wherein the removable adjuster defines an aperture to receivethe shaft.
 8. The internal valve as defined in claim 1, wherein theremovable adjuster is coaxially aligned with the bore of the secondbody.
 9. The internal valve as defined in claim 1, wherein the boredefines a stepped portion to limit the movement of the removableadjuster relative to the second body.
 10. The internal valve as definedin claim 1, wherein the bonnet assembly further comprises a springpositioned within the bore to exert a force on the valve packing. 11.The internal valve as defined in claim 1, wherein the bonnet assembly isremovably coupled to the body via a plate.
 12. The internal valve asdefined in claim 1, wherein the second body is provided with exteriorthreads to removably couple the bonnet assembly to the first body.
 13. Afield removable bonnet assembly for use with internal valves,comprising: a body that is to be removably coupled to the internalvalve, wherein the body defines a bore that is to receive a valvepacking; a shaft having a cam assembly that is to rotatably engage astem of the internal valve, wherein the shaft is rotatably coupled tothe body and wherein the shaft is at least partially positioned withinthe bore; and a removable adjuster that is externally accessible toenable an adjustment of the removable adjuster relative to the body tochange a force exerted by the valve packing on the shaft, wherein theremovable adjuster is field removable to replace or repair the valvepacking.
 14. The field removable bonnet assembly as defined in claim 13,wherein the removable adjuster further comprises an indicator toindicate an adjustment position of the removable adjuster relative tothe body.
 15. The field removable bonnet assembly as defined in claim13, wherein the removable adjuster further defines at least one slot tobe engaged by a tool to enable the adjustment of the removable adjusterrelative to the body.
 16. The field removable bonnet assembly as definedin claim 15, wherein a position of the at least one slot is to indicatean adjustment position of the removable adjuster relative to the body.17. The field removable bonnet assembly as defined in claim 13, whereinthe removable adjuster comprises an elongated member that extends fromthe body to enable the adjustment of the removable adjuster relative tothe body.
 18. The field removable bonnet assembly as defined in claim13, wherein the removable adjuster threadingly engages the body.
 19. Thefield removable bonnet assembly as defined in claim 13, wherein theremovable adjuster defines an aperture to receive the shaft.
 20. Thefield removable bonnet assembly as defined in claim 13, wherein theremovable adjuster is coaxially aligned with the bore.
 21. The fieldremovable bonnet assembly as defined in claim 13, wherein the boredefines a stepped portion to limit the movement of the removableadjuster relative to the body.
 22. The field removable bonnet assemblyas defined in claim 13, wherein the body is provided with exteriorthreads to removably couple the bonnet assembly to the internal valve.23. A field removable bonnet assembly for use with internal valves,comprising: a body that is to be removably coupled to the internalvalve, wherein the body comprises means for receiving a valve packing; ashaft comprising means for rotably engaging a stem of the internalvalve, wherein the shaft is at least partially positioned within themeans for receiving the valve packing and wherein the shaft is rotatablycoupled to the body; means for rotating the shaft relative to the body;and means for externally adjusting a force exerted by the valve packingon the shaft.
 24. The field removable bonnet assembly as defined inclaim 23, wherein the means for externally adjusting the force exertedby the valve packing on the shaft comprises a removable adjuster that isfield removable to replace or repair the valve packing.